1. Field of the Invention:
The present invention relates to a method of detecting the quantity of replenishing solution remaining in a replenishing-solution tank by performing calculations based on the quantity of light sensitive material processed.
2. Description of the Related Art:
Automatic developing machines are in general arranged in such a manner that a light sensitive material which has been exposed is passed through a developing tank, a fixing tank, and a washing tank and is discharged after drying. In this case, after the light sensitive material has been immersed, for example, in the developer in the developing tank, the light sensitive material is fed to the next fixing tank, with a portion of the developer adhering to the surface of the light sensitive material. As a result, the quantity of developer decreases in accordance with the quantity of light sensitive material processed. In addition, since the developer gradually deteriorates due to the processing of light sensitive material and the aging of the developer itself, it is necessary to periodically supply a replenishing solution containing a large amount of developing agent.
Such an automatic developing machine is provided with a replenishing-solution tank which communicates with the developing tank through a pipe, and the replenishing solution can be supplied to the developing tank by the driving of the pump. More specifically, a previously prepared replenishing solution which is stored in the replenishing-solution tank is supplied as required to the developing tank by the driving of the pump. Therefore, an operator can easily perform the operation of supplying a replenishing solution without the need to prepare the replenishing solution for each supply thereof.
In general, since the replenishing-solution tank is limited in volume, the operator needs to confirm the quantity of replenishing solution remaining in the replenishing-solution tank and, if the remaining quantity of replenishing solution is small, he must prepare the replenishing solution and supply it to the replenishing-solution tank. For this reason, the replenishing-solution tank is commonly made of a transparent or translucent material which permits the liquid level in the replenishing-solution tank to be viewed from the exterior, and the replenishing-solution tank is provided with a plurality of equally spaced cuts parallel to the liquid level. Accordingly, the operator can readily detect the quantity of replenishing solution remaining in the replenishing-solution tank.
However, such a structure of the replenishing-solution tank has involved the problem that, when the replenishing-solution tank itself is contaminated, the operator may have difficulty in identifying the liquid level and there is a possibility that he may misread the remaining quantity. In addition, in order to facilitate confirmation of the remaining quantity, at least a portion of the replenishing-solution tank must be exposed to the exterior of the automatic developing machine. Furthermore, since cuts must be formed in the replenishing-solution tank, the production of such replenishing solution tanks requires complicated processes.
To obviate the problems, a structure has been proposed in which the minimum liquid level (a lower level) at least to which a replenishing solution must be charged into the replenishing-solution tank is set and a sensor for detecting the fact that the quantity of replenishing solution has reached the lower level is incorporated, whereby an alarm generates an alarm sound when the sensor has detected that fact (alarm structure). When an operator confirms the alarm sound generated by the alarm, he prepares a predetermined quantity of replenishing solution and supplies it to the replenishing-solution tank. Thus, the replenishing solution is prevented from running short in the replenishing-solution tank.
However, such an alarm structure involves a small time lag between the starting of operation of the alarm and the starting of supply of the replenishing solution to the replenishing-solution tank, and the replenishing solution may be supplied to the developing tank during the period of the time lag as well. For this reason, even if the predetermined quantity of replenishing solution is supplied to the replenishing-resolution tank after the operation of the alarm, the quantity of replenishing solution in the replenishing-solution tank may actually not reach the upper level. In such an alarm structure, even if it is desired to fully charge the replenishing-solution tank (for example, in the absence of an operator and during a 24-hour continuous operation of the automatic developing machine), it is impossible to confirm an accurate remaining quantity in the replenishing-solution tank. Accordingly, it is necessary to prepare a replenishing-solution tank having a complicated structure, such as one provided with a reservoir pipe.